SKINSKIN

Cutaneous membraneCutaneous membrane

Integumentary systemIntegumentary system

INTEGUMENTARY SYSTEMINTEGUMENTARY SYSTEM

Means “covering”Means “covering” Consists of Skin, sweat glands, oil Consists of Skin, sweat glands, oil

glands, hairs and nailsglands, hairs and nails

SKINSKIN Basic FunctionsBasic Functions– To protectTo protect– To insulateTo insulate– To cushionTo cushion

The skin protects deeper tissues from The skin protects deeper tissues from – Mechanical damageMechanical damage– Chemical damageChemical damage– Bacterial damageBacterial damage– Ultraviolet radiation (damaging effects of sunlight)Ultraviolet radiation (damaging effects of sunlight)– Thermal (heat or cold) damageThermal (heat or cold) damage– Desiccation (drying out)Desiccation (drying out)

Aids in body heat loss or heat retention Aids in body heat loss or heat retention (controlled by the nervous system)(controlled by the nervous system)

Aids in excretion of urea and uric acidAids in excretion of urea and uric acid Synthesizes vitamin D Synthesizes vitamin D

STRUCTURE OF THE SKINSTRUCTURE OF THE SKIN 2 kinds of tissue 2 kinds of tissue

11 EPIDERMISEPIDERMIS- (stratified squamous) - (stratified squamous) KERATINOCYTESKERATINOCYTES – cells which – cells which produce produce KERATINKERATIN- fibrous protein - fibrous protein that makes the skin become hard and that makes the skin become hard and toughtough

22 DERMIS- DERMIS- dense connective tissue dense connective tissue firmly connected to epidermis, but firmly connected to epidermis, but can separate and form a blister-can separate and form a blister-

STRUCTURE OF THE SKINSTRUCTURE OF THE SKIN

SUBCUTANEOUS SUBCUTANEOUS TISSUE TISSUE (HYPODERMIS)- (HYPODERMIS)- not considered not considered skin- adipose tissue skin- adipose tissue that anchors skin that anchors skin to surrounding to surrounding organsorgans

EPIDERMISEPIDERMIS

5 LAYERS CALLED STRATA- all layers 5 LAYERS CALLED STRATA- all layers are avascular- has no blood supplyare avascular- has no blood supply

EPIDERMISEPIDERMIS

STRATUM BASALE- single bottom STRATUM BASALE- single bottom layer of epidermis- columnar in layer of epidermis- columnar in shape- receive the most shape- receive the most nourishment-constantly undergoing nourishment-constantly undergoing cell division with all the new cell division with all the new daughter cells pushed upwardsdaughter cells pushed upwards

EPIDERMISEPIDERMIS

STRATUM SPINOSUM-spiny layer of STRATUM SPINOSUM-spiny layer of cuboidal cells- nuclei appear dark- cuboidal cells- nuclei appear dark- first signs of cell death first signs of cell death

EPIDERMISEPIDERMIS STRATUM STRATUM

GRANULOSUM- GRANULOSUM- partially flattened partially flattened cells whose cells whose cytoplasm cytoplasm contains small contains small granular proteins granular proteins that are in the that are in the process of turning process of turning into keratin- into keratin- nucleus begins to nucleus begins to disappeardisappear

EPIDERMISEPIDERMIS STRATUM LUCIDUM STRATUM LUCIDUM

– clear layer- 3 to 4 – clear layer- 3 to 4 rows of cells that rows of cells that are flattened and are flattened and now dead- keratin now dead- keratin formation continuesformation continues

– is only where the is only where the skin is hairless and skin is hairless and extra thick, palm of extra thick, palm of the hands and the hands and soles of the feetsoles of the feet

EPIDERMISEPIDERMIS

STRATUM CORNEUM-most superficial STRATUM CORNEUM-most superficial layer- 20-50 cells thick accounts for layer- 20-50 cells thick accounts for 75% of the skins thickness75% of the skins thickness

slowly rubs and flakes off and is slowly rubs and flakes off and is replaced by cells produced by the replaced by cells produced by the division of the deeper stratum division of the deeper stratum basale cells. Every 25 to 45 days we basale cells. Every 25 to 45 days we have a “new” epidermis.have a “new” epidermis.

KERATINOCYTESKERATINOCYTES

KeratinKeratin is found the stratum is found the stratum corneum and is a tough protein corneum and is a tough protein that provides a durable “overcoat” that provides a durable “overcoat” for the body, protecting the for the body, protecting the deeper cells from the hostile deeper cells from the hostile external environment. It also external environment. It also protects them from water loss and protects them from water loss and helps the body resist biological, helps the body resist biological, chemical, and physical assaultchemical, and physical assault

MELANOCYTESMELANOCYTES MelaninMelanin is a pigment that ranges in is a pigment that ranges in

color from yellow to brown to black color from yellow to brown to black and is mainly found in the stratum and is mainly found in the stratum basale. Sunlight stimulates the basale. Sunlight stimulates the melanocytes to produce melanin, melanocytes to produce melanin, tanning occurs. The stratum basale tanning occurs. The stratum basale cells phagocytize the pigment, cells phagocytize the pigment, accumulating it within them. The accumulating it within them. The melanin forms a protective pigment melanin forms a protective pigment “umbrella” over the nuclei that “umbrella” over the nuclei that shields their genetic material from shields their genetic material from the damaging effects UV RAYS. the damaging effects UV RAYS. Freckles and moles are seen where Freckles and moles are seen where melanin is concentrated in one spotmelanin is concentrated in one spot

DERMISDERMIS The dermis is a strong, stretchy envelope that The dermis is a strong, stretchy envelope that

helps to hold the body togetherhelps to hold the body togetherContains collagen and elastic fibersContains collagen and elastic fibersCollagenCollagen- provides toughness, also attracts and - provides toughness, also attracts and

binds to water to keep skin hydratedbinds to water to keep skin hydratedElasticElastic- provides elasticity- provides elasticity It varies in thickness, thick on the palms of the It varies in thickness, thick on the palms of the

hand and soles of the feet, but quite thin on the hand and soles of the feet, but quite thin on the eye lidseye lids

Consists of two regionsConsists of two regions1.1. PAPILLARY LAYER- upper regionPAPILLARY LAYER- upper region2.2. RETICULAR LAYER- lower regionRETICULAR LAYER- lower region

DERMISDERMIS

PAPILLARY LAYER – PAPILLARY LAYER – (upper)-contains (upper)-contains dermal papillaedermal papillae

DERMAL PAPILLAEDERMAL PAPILLAE- uneven - uneven fingerlike projections from its superior fingerlike projections from its superior surface (fingerprints)- these projections surface (fingerprints)- these projections can house many thingscan house many things

Capillary Loops-Capillary Loops- Free nerve endings (pain receptors)Free nerve endings (pain receptors) Meissner’s corpuscles- (touch Meissner’s corpuscles- (touch

receptors)receptors)

DERMISDERMIS

DERMAL PAPILLAE can house DERMAL PAPILLAE can house many thingsmany things

1.1. Capillary Loops- which can Capillary Loops- which can increase / decrease blood flow to skinincrease / decrease blood flow to skin

2.2. Free nerve endings (pain Free nerve endings (pain receptors) some receptors detect receptors) some receptors detect hot or cold.hot or cold.

3.3. Meissner’s corpuscles- (touch Meissner’s corpuscles- (touch receptors)receptors)

DERMISDERMIS

RETICULAR LAYER – RETICULAR LAYER – (deep)-(deep)-

ContainsContains

1. BLOOD VESSELS1. BLOOD VESSELS

2. SUDORIFEROUS 2. SUDORIFEROUS GLANDS-(sweat) (2 GLANDS-(sweat) (2 types)types)

3. SEBACEOUS GLANDS- 3. SEBACEOUS GLANDS- (oil)(oil)

4. PACINIAN 4. PACINIAN CORPUSCLES- deep CORPUSCLES- deep pressure receptorspressure receptors

SUDORIFEROUS GLANDS-SUDORIFEROUS GLANDS-

Two typesTwo types1.1. ECCRINE GLANDS more numerous and ECCRINE GLANDS more numerous and

produce sweat- produce sweat- SWEATSWEAT – contains – contains

1.1. waterwater2.2. sodium chloridesodium chloride3.3. vitamin Cvitamin C4.4. metabolic waste metabolic waste

(ammonia, urea)(ammonia, urea)5.5. lactic acid (attracts lactic acid (attracts

mosquitos)mosquitos)

SUDORIFEROUS GLANDS-SUDORIFEROUS GLANDS-

FUNCTIONS OF SWEATFUNCTIONS OF SWEAT

1.1. Evaporation of sweat off the skins Evaporation of sweat off the skins surface gives cooling effectsurface gives cooling effect

2.2. Acidic (pH of 4-6) inhibits bacteria Acidic (pH of 4-6) inhibits bacteria growthgrowth

SUDORIFEROUS GLANDS-SUDORIFEROUS GLANDS-

2.2. APOCRINE GLANDS- found only in the APOCRINE GLANDS- found only in the armpit and genital areasarmpit and genital areas

SECRETION contains fatty acids SECRETION contains fatty acids and proteins (yellowish or milky color)and proteins (yellowish or milky color)

The secretion is odorless but The secretion is odorless but bacteria can grow from it giving off an bacteria can grow from it giving off an unpleasant odor.unpleasant odor.

SEBACEOUS GLANDS (oil SEBACEOUS GLANDS (oil glands)glands)

Typically located near hair follicle and Typically located near hair follicle and dump secretions (SEBUM) there.dump secretions (SEBUM) there.

SEBUM- lubricant that keeps skin soft SEBUM- lubricant that keeps skin soft and moist. Keeps hair from and moist. Keeps hair from becoming brittle. Also contains becoming brittle. Also contains chemicals to kill bacteria.chemicals to kill bacteria.

SEBACEOUS GLANDS (oil SEBACEOUS GLANDS (oil glands)glands)

If a sebaceous gland becomes blocked If a sebaceous gland becomes blocked a WHITEHEAD APPEARSa WHITEHEAD APPEARS

If that material oxidizes and dries then If that material oxidizes and dries then a BLACKHEAD FORMSa BLACKHEAD FORMS

SKIN COLORSKIN COLOR

3 pigments contribute 3 pigments contribute

1.1.MELANIN in the epidermis (amounts and MELANIN in the epidermis (amounts and types)types)

2.2.CAROTENE- (orange-yellow pigment found CAROTENE- (orange-yellow pigment found in carrots)- found in the stratum corneum in carrots)- found in the stratum corneum and subcutaneous tissueand subcutaneous tissue

3.3.Amount of OXYGEN bound to hemoglobin Amount of OXYGEN bound to hemoglobin of Red blood Cells- when poorly of Red blood Cells- when poorly oxygenated skin appear blue called oxygenated skin appear blue called CYANOSISCYANOSIS

HAIRHAIR Is a flexible outgrowth of dead (KERATINIZED) Is a flexible outgrowth of dead (KERATINIZED)

epithelial cellsepithelial cells In earlier humans hair provided insulation in cold In earlier humans hair provided insulation in cold

weatherweather It has a few minor protective functionsIt has a few minor protective functions

– Guarding the head against bumpsGuarding the head against bumps– Shields the eye (eyelashes)Shields the eye (eyelashes)– Helps to keep foreign particles out of the respiratory Helps to keep foreign particles out of the respiratory

tract (nose hairs)tract (nose hairs) Has 3 layersHas 3 layers

– Medulla~inner mostMedulla~inner most– Cortex~middle bulky areaCortex~middle bulky area– Cuticle~outermost, single layerCuticle~outermost, single layer

LAYERS OF HAIRLAYERS OF HAIR

The MEDULLA is a honeycomb structure of The MEDULLA is a honeycomb structure of keratin and air spaces keratin and air spaces

LAYERS OF HAIRLAYERS OF HAIR

The CORTEX gives flexibility and tensile The CORTEX gives flexibility and tensile strength to hair and contains melanin strength to hair and contains melanin (giving hair its color). Without melanin, the (giving hair its color). Without melanin, the partly hollow hair appears grey.partly hollow hair appears grey.

LAYERS OF HAIRLAYERS OF HAIR The CUTICLE is made from 6 to 11 layers of The CUTICLE is made from 6 to 11 layers of

overlapping semi-transparent scales (which make overlapping semi-transparent scales (which make the hair waterproof and allow it to be stretched). the hair waterproof and allow it to be stretched). Someone with thick, course hair will have more Someone with thick, course hair will have more overlapping layers of cuticles that someone with overlapping layers of cuticles that someone with fine hair. fine hair.

HAIRHAIRShaftShaft is the part exposed above the skin is the part exposed above the skin

RootRoot is the part below the surface surrounded by the is the part below the surface surrounded by the hair folliclehair follicle

Arrector PilliArrector Pilli Muscles Muscles are the smooth muscle cells are the smooth muscle cells which are attached to dermal tissue and follicle which are attached to dermal tissue and follicle which can contract and produce “goose bumps”. It’s which can contract and produce “goose bumps”. It’s purpose is to keep warm. (Hair follicles are always at purpose is to keep warm. (Hair follicles are always at an angle and the arrector pilli muscles reduce that an angle and the arrector pilli muscles reduce that angle)angle)

Hair Bulb MatrixHair Bulb Matrix is the area at the (inferior) end of is the area at the (inferior) end of the root where cell stratum basale epithelial cells the root where cell stratum basale epithelial cells rapidly divides promoting hair growth (1 mm every 3 rapidly divides promoting hair growth (1 mm every 3 days)days)

MelanocytesMelanocytes are located in the stratum basale layer are located in the stratum basale layer which give your hair its colorwhich give your hair its color

HAIRHAIR

HAIR BULB MATRIX (growth HAIR BULB MATRIX (growth zone)zone)

Consists of:Consists of:

1.1. PAPILLAPAPILLA- well vascularized - well vascularized connective tissue that goes up into the connective tissue that goes up into the hair bulbhair bulb

2.2. STRATUM BASALE-STRATUM BASALE- one layer of one layer of cells around Papilla- where hair growth cells around Papilla- where hair growth occursoccurs

HAIR BULB MATRIXHAIR BULB MATRIX

NailsNails

Three parts of the nailThree parts of the nail1.1. BodyBody~area that is visible~area that is visible

2.2. Free EdgeFree Edge~area that ~area that overhangs the digitoverhangs the digit

3.3. RootRoot~area covered by ~area covered by nail folds, embedded in the skinnail folds, embedded in the skin

A scalelike modification of the epidermis A scalelike modification of the epidermis that corresponds to hoofs or claws that corresponds to hoofs or claws

Nearly colorless except they look pink due Nearly colorless except they look pink due to rich blood supply in the dermis beneathto rich blood supply in the dermis beneath

NailsNails

Nail FoldsNail Folds are are the the overlapping overlapping skin of the nailskin of the nail

CUTICLECUTICLE is the is the thick proximal thick proximal nail foldnail fold

NailsNails

Nail MatrixNail Matrix is the is the area responsible area responsible for nail growthfor nail growth

As the nail cells As the nail cells are produced by are produced by the matrix, they the matrix, they become heavily become heavily keratinized and diekeratinized and die

BURNSBURNS

BURN- tissue damage and cell death BURN- tissue damage and cell death caused by intense heat, electricity, UV caused by intense heat, electricity, UV radiation, or chemicalsradiation, or chemicals

2 LIFE THREATENING PROBLEMS RESULT2 LIFE THREATENING PROBLEMS RESULT1.1. Loss of fluids- ( proteins and Loss of fluids- ( proteins and electrolytes) Leads to dehydration, electrolytes) Leads to dehydration, circulatory shock, kidney shutdowncirculatory shock, kidney shutdown2.2. Infection - bacteria or fungi infecting Infection - bacteria or fungi infecting deeper unprotected tissuesdeeper unprotected tissues

SEVERITY OF BURNSSEVERITY OF BURNS

FIRST DEGREE BURNSFIRST DEGREE BURNS- only - only epidermis is damaged- temporary epidermis is damaged- temporary discomfort. (most sunburns)discomfort. (most sunburns)

SEVERITY OF BURNSSEVERITY OF BURNS

SECOND DEGREE BURNSSECOND DEGREE BURNS- injury to - injury to epidermis and upper region of epidermis and upper region of dermis- Blisters will appear- but skin dermis- Blisters will appear- but skin will regeneratewill regenerate

THIRD DEGREE BURNSTHIRD DEGREE BURNS

Third degree burns destroy all three layers of Third degree burns destroy all three layers of the skin. Regeneration of the skin is the skin. Regeneration of the skin is impossible because blood vessels have been impossible because blood vessels have been destroyed. The good news is that Nerve destroyed. The good news is that Nerve endings have also been destroyed. NO endings have also been destroyed. NO PAIN!!! YEAH!PAIN!!! YEAH!

THIRD DEGREE BURNSTHIRD DEGREE BURNS

Burned areas Burned areas appear gray-white appear gray-white or blackenedor blackened

Skin transplants Skin transplants are necessaryare necessary

SKIN CANCERSKIN CANCER

-Skin Cancer is the single most common -Skin Cancer is the single most common cancer in humans. cancer in humans.

-Although most skin tumors are benign -Although most skin tumors are benign and to not spread to other body organs, and to not spread to other body organs, some can be malignant or cancerous. some can be malignant or cancerous.

-Single biggest risk factor is -Single biggest risk factor is overexposure to the sunoverexposure to the sun

- Other risk factors include skin - Other risk factors include skin infections, chemicals, or physical infections, chemicals, or physical traumatrauma

BASAL CELL CARCINOMABASAL CELL CARCINOMA-- most common and least malignant type of most common and least malignant type of

skin cancer. skin cancer. Stratum Basale cells are altered to where Stratum Basale cells are altered to where

they no longer distinguish the boundary of they no longer distinguish the boundary of epidermis and dermis. New dividing cells epidermis and dermis. New dividing cells are pushed in all directions including into are pushed in all directions including into the dermis and subcutaneous layers. the dermis and subcutaneous layers.

- appears as a dome shaped nodule that - appears as a dome shaped nodule that develops a central ulcer with a pearly develops a central ulcer with a pearly beaded edgebeaded edge

- 99% curable if cancer is surgically - 99% curable if cancer is surgically removed.removed.

SQUAMOUS CELL SQUAMOUS CELL CARCINOMACARCINOMA--

arises from the stratum spinosumarises from the stratum spinosum - appears as a small rounded elevation - appears as a small rounded elevation

that is red and scaly which gradually that is red and scaly which gradually forms a shallow ulcer with a firm raised forms a shallow ulcer with a firm raised borderborder

- appears most often on the scalp, - appears most often on the scalp, ears, back of the hand, and lower lip.ears, back of the hand, and lower lip.

- can become malignant and invade - can become malignant and invade adjacent lymph nodes if not removed.adjacent lymph nodes if not removed.

MALIGNANT MELANOMAMALIGNANT MELANOMA--

cancer of the melanocytes- occurs cancer of the melanocytes- occurs wherever there are pigment. wherever there are pigment.

- accounts for only 5% of cancers - accounts for only 5% of cancers - develop spontaneously or from - develop spontaneously or from

pigmented molespigmented moles -rapidly spread and attack -rapidly spread and attack

surrounding lymph and blood vesselssurrounding lymph and blood vessels -chance for survival 50%-chance for survival 50%

When should you worry about When should you worry about a mole being cancerous?a mole being cancerous?

FOLLOW THE ABCD RULE (pg 111)- FOLLOW THE ABCD RULE (pg 111)- AsymmetryAsymmetry, , BorderBorder irregularityirregularity (lesion is not (lesion is not

smooth but has indentions), smooth but has indentions), Color Color (blacks, browns, tans, blues (blacks, browns, tans, blues

and reds) and reds) Diameter Diameter (more than 6 mm)(more than 6 mm)

BURNS- RULES OF 9BURNS- RULES OF 9

RULE of NINES- body is divided into RULE of NINES- body is divided into 11 areas that each account for 9 % 11 areas that each account for 9 %

Example- 4.5 % front of arm, 4.5 % Example- 4.5 % front of arm, 4.5 % back of arm, front of leg 9%, back of back of arm, front of leg 9%, back of leg 9% leg 9%

  

BURNSBURNS

Burns are considered critical if:Burns are considered critical if:

1. Over 25 % of the body has second 1. Over 25 % of the body has second degree burnsdegree burns

2. Over 10 % of the body has third 2. Over 10 % of the body has third degree burndegree burn

3. There are third degree burns of the 3. There are third degree burns of the face, hands, or feetface, hands, or feet

How does the skin react to How does the skin react to Heat or cold?Heat or cold?

HEATHEAT 1. Nerves in dermal papillae send 1. Nerves in dermal papillae send

signals to brain (hypothalamus) of signals to brain (hypothalamus) of temp. changetemp. change

2. Capillaries are opened up completely 2. Capillaries are opened up completely to allow blood to RADIATE out heatto allow blood to RADIATE out heat

3. ECCRINE GLANDS are activated to 3. ECCRINE GLANDS are activated to allow sweat evaporation to cool the allow sweat evaporation to cool the body.body.

If body gets too HOTIf body gets too HOT

HEAT EXHAUSTION or HEAT STROKE HEAT EXHAUSTION or HEAT STROKE can occurcan occur

How does the skin react to How does the skin react to Heat or cold?Heat or cold?

COLDCOLD

1. Nerves in dermal papillae send signals to brain 1. Nerves in dermal papillae send signals to brain (hypothalamus) of temp. change(hypothalamus) of temp. change

2. VASOCONSTRICTION of blood vessels and 2. VASOCONSTRICTION of blood vessels and vascular shunts redirect blood away from the vascular shunts redirect blood away from the capillaries (surface)capillaries (surface)

3. Keeps blood near the core for warmth3. Keeps blood near the core for warmth

4. ARRECTOR PILI MUSCLES – contract to form an 4. ARRECTOR PILI MUSCLES – contract to form an extra layer of insulationextra layer of insulation

5. If body temperature is still too low the SHIVERING 5. If body temperature is still too low the SHIVERING occurs to produce more heat. occurs to produce more heat.

If the body gets too coldIf the body gets too cold

FROSTBITE or HYPOTHERMIA can set FROSTBITE or HYPOTHERMIA can set in .in .

The AGING of SKINThe AGING of SKIN

As Adults get older-As Adults get older-

1.1. Amount of SUBCUTANEOUS TISSUE Amount of SUBCUTANEOUS TISSUE decreases (less insulation)decreases (less insulation)

2.2. Amount of OIL decreases (drier, itchier)Amount of OIL decreases (drier, itchier)

3.3. Layers of skin become thinnerLayers of skin become thinner

4.4. Loss of collagen and elastin fibersLoss of collagen and elastin fibers

More susceptible to cold, bruising, and other More susceptible to cold, bruising, and other types of injuriestypes of injuries

Other problems with aging Other problems with aging skinskin

1.1. Loss of elasticity and subcutaneous tissue Loss of elasticity and subcutaneous tissue causes skin to SAG (Example- bags under causes skin to SAG (Example- bags under the eyes, jowls begin to sag)the eyes, jowls begin to sag)

MAJOR CAUSES- exposure to sun, dehydration, MAJOR CAUSES- exposure to sun, dehydration, poor nutrition, poor sleeping habits poor nutrition, poor sleeping habits

2.2. Loss of hair follicles-- ALOPECIA- “thinning Loss of hair follicles-- ALOPECIA- “thinning of the hair”of the hair”

3.3. MALE PATTERN BALDNESS- caused by loss MALE PATTERN BALDNESS- caused by loss of testosteroneof testosterone